17:38⎜«hondza:#mksh» so I built new mksh, run tests and got:

17:38⎜«hondza:#mksh» fail ../mksh/check.t:IFS-space-colon-3 (as expected)
17:38⎜«hondza:#mksh» FAIL ../mksh/check.t:integer-base-5
17:39⎜<mirabile:#mksh> interesting
17:40⎜<mirabile:#mksh> why does integer-base-5 fail?
17:40⎜«hondza:#mksh»     j=~3
17:40⎜«hondza:#mksh» ~3 expands to /tmp/3
17:40⎜<mirabile:#mksh> aah, nice catch
17:40⎜<mirabile:#mksh> that must be quoted of course. bug in the test.
17:41⎜<mirabile:#mksh> can you try with j='~3'
17:41⎜<mirabile:#mksh> I'll commit that in an instant then
17:42⎜«hondza:#mksh» yeah, quoting it worked
17:42⎜<mirabile:#mksh> thanks
17:42⎜«hondza:#mksh» :)

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.63 2006/08/28 01:40:54 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.64 2006/08/28 17:42:55 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -2350,7 +2350,7 @@ stdin:
 	echo $a
 	echo --
 	typeset -i j=3
-	j=~3
+	j='~3'
 	echo $j
 	echo --
 	typeset -i k=1